0.60 M of NaOH flows into a tubular reactor at a rate of 90 ml/min to be mixed isothermally with 0.60 M of ethyl acetate flowing with a rate of 90 ml/min, given that the volume of tubular reactor is 400 ml and NaOH steady state concentration is 0.032 M, then the value reaction rate constant at flow rate of 80 ml/min for both reactants is :